Ординатура / Офтальмология / Английские материалы / Atlas of Lacrimal Surgery_Weber, Keerl, Della Rocca_2007

To dry people’s eyes – that’s one of the great challenges in lacrimal surgery. Different localizations of the stenosis, lesions after tumor surgery or trauma, and epiphora in children or adults are different conditions that need various operative procedures to treat a patient individually and successfully.

The close relationship between the eyes and nose demands an interdisciplinary approach to lacrimal surgery.Therefore,ophthalmologists,otorhinolaryngologists as well as plastic surgeons are invited to contribute in solving a patient’s problem.

This book is intended to serve as a practically oriented reference. In the first part, it contains chapters on pertinent surgical anatomy, physiology and pathophysiology as well as basic clinical and radiological evaluation. In the second part, well-known authorities from all over the world present their experience in all operative procedures currently available to dry

patients’ eyes. The accompanying DVD contains video clips of different operations highlighting key portions of these procedures.

I would like to express my gratitude to Springer, especially to Ms. Marion Philipp and Ms. Martina

Himberger, and would also like to thank Alan Bellinger for reading and improving the manuscript. Additionally, I owe many thanks to my editorial colleagues, who did a great job working together on this book and to the authors who prepared excellent articles.

Finally, I wish all readers much pleasure while working through the chapters and hope that it helps them reach the goal of satisfied patients with dry eyes.

Rainer K. Weber

Core Messages!

ΘThe tear film is produced by the lacrimal gland and the different structures of the eye lid. Its composition is controlled by the lacrimal functional unit.

ΘThe ocular surface epithelia together with the lacrimal gland produce a unique subset of membrane bound and secretory mucins that stabilize the tear film, fix it to the epithelia, support binding of bacteria, and are of great importance to tear physiology.

ΘTFF peptides TFF1 and TFF3 of conjunctival origin influence the rheological properties of the tear film.

ΘDrainage of tears involves a number of different mechanisms; of these the action of the lacrimal part of the orbicularis oculi muscle is most important to bring tear fluid into the lacrimal sac. Epithelial secretion products, the surrounding cavernous body, and the arrangement of connective tissue fibers are most important to drain lacrimal fluid from the lacrimal sac into the inferior meatus of the nose.

ΘThe epithelium of the nasolacrimal ducts eases tear flow by the production of mucins and TFF peptides. Moreover, it contributes to antimicrobial defense and is able to absorb tear fluid components.

ΘThe lacrimal sac and nasolacrimal duct are surrounded by a cavernous body. While regulating the blood flow, the specialized blood vessels permit opening and closing of the lumen of the lacrimal passage affected by the bulging and subsiding of the cavernous body, while at the same time regulating tear outflow. The blood vessels are connected to the vessels of the outer eye and could act as a feedback signal for tear-fluid production.

Contents

1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1.2Anatomy and Physiology

of the Ocular Surface and Adnexa . . . . . . . . . . . . . . . . 2

1.2.1 Ocular Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2.2 Lacrimal Gland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.3 Eyelid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2.4 The Lacrimal Functional Unit . . . . . . . . . . . . . . . . . . . . 5

1.3Anatomy and Physiology

of the Nasolacrimal Ducts . . . . . . . . . . . . . . . . . . . . . . . 6 1.3.1 Innate Immune Mechanisms . . . . . . . . . . . . . . . . . . . . 8 1.3.2 Adaptive Immune Mechanisms . . . . . . . . . . . . . . . . . . 9 1.3.3 Mechanisms of Tear Drainage. . . . . . . . . . . . . . . . . . . . 10 1.3.4 Absorption of Tear-Fluid Components . . . . . . . . . . . . 12

1.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1.1 Introduction

Study of the nasolacrimal ducts is a synthesis of two disciplines, ophthalmology and otorhinolaryngology, which work closely together in the treatment of nasolacrimal disorders. During recent years a bulk of new diagnostic and therapeutic methods, such as nasolac-

rimal endoscopy, laser-assisted dacryocystorhinosto-

1my, transcanalicular surgery, and interventional radiological therapies, have been applied to the nasolacrimal system; however, common knowledge about anatomy and physiology of the nasolacrimal ducts, and of tear flow through the nasolacrimal passage, is not well developed.

This chapter summarizes recent advances in knowledge of the nasolacrimal ducts and discusses them in conjunction with nasolacrimal duct physiology.

1.2Anatomy and Physiology

of the Ocular Surface and Adnexa

To understand the physiology of tear flow through the nasolacrimal passage, and also its pathophysiology (Chap. 2), basic knowledge of the whole lacrimal system is necessary. The ocular surface and its adnexa comprise the cornea, the conjunctiva with bulbar, fornical and palpebral parts, the main lacrimal gland, and the glands of the eye lids, i.e., Meibomian, Moll,

Zeis, and accessory lacrimal glands as well as the

nasolacrimal system; the latter consists of the upper and lower puncta, the paired lacrimal canaliculi, the lacrimal sac, and the nasolacrimal duct (Fig. 1.1). The nasolacrimal ducts collect the tear fluid from the ocular surface and convey it into the nasal cavity, whereas all other structures contribute to formation of the preocular and cornea tear film. The tear film serves to protect and lubricate the ocular surface, allowing for protection of the cornea and consistent clarity of vision.

The preocular tear film contains water, protective antimicrobials, cytokines, lipids, and mucins, and is divided into three components: a lipid, an aqueous, and a mucus component. The lipid component is secreted by the Meibomian glands in the eyelid and forms the superficial layer of the tear film (Fig. 1.2). The aqueous component contains electrolytes, water, and a large variety of proteins, peptides, and glycopeptides, and is secreted primarily by the lacrimal gland as well as the accessory lacrimal glands (glands of Krause, glands of Wolfring) of the lids (Fig. 1.2). The mucus component is the product of conjunctival goblet and epithelial cells, corneal epithelial cells [4], and acinar as well as excretory duct cells of the lacri-